Session Initiation Protocol (SIP) is a signaling protocol used for establishing sessions in an Internet Protocol (IP) network. There are various commercial and open-source implementations of SIP, which may differ significantly in their interfaces and SIP features/functionality they provide. Typically, systems using SIP also require some additional capabilities beyond basic signaling services. Systems such as IP Video Phone (IPVP), for example, may require call conferencing, multi-call support, media negotiation, and Network Address Translator (NAT) traversal. The above-mentioned requirements may involve significant system design variations and development efforts, depending on various factors such as end application and deployment scenarios.
Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.